Much work is presently being done to ignite and burn fusion fuel such as, for example, deuterium-tritium in pellet form. While there are a number of different approaches to this problem, one of them includes the utilization of a source of energy from a laser and particular pellet configurations to achieve ignition and burn in a reaction chamber. Recent activity shows the successful generation of high intensity neutrons by this method. One publication UCRL 76857, July 1975 from Lawrence Livermore Laboratory describes a most intense source of DT fusion neutrons currently available. Laser Focus, Sept. 1975, pp. 39-42, shows evidence of large neutron yields from both KMS Fusion, Inc. and Livermore. Thus fusion reactions are a preferred source of radiation, although many other sources of gamma, alpha, X ray and neutron radiation devices are currently available in commercial form.
U.S. Patents which illustrate generally the apparatus which can be used in this type of system are:
Whittlesey: 3,378,446 -- Apr. 16, 1968 PA1 Daiber: 3,489,645 -- Jan. 13, 1970 PA1 Hedstrom: 3,762,992 -- Oct. 2, 1973
It has been proposed to use nuclear reactors for the dissociation of water to hydrogen and oxygen in one step, at least as early as 1962 in the British Pat. No. 908,469 to Manfred Siebker, for example. The one-step process can take place from high temperature but preferably involves radiation dissociation caused by neutrons, alpha, or X radiation caused by exposing the target molecule directly to radiation from a fusion or fission source to produce the desired product. The use of radiation from thermo-nuclear fusion reactors has a significant advantage over the use of radiation from fission in such processes.
When the fission process is used as a radiation source materials must be exposed directly to the fission fragments in order to obtain effective energy transfer and this also requires that the material be exposed to uranium or plutonium fuel directly. In some instances, the use of uranium dust to be mixed with the reactants is recommended. (See Advances in Nuclear Science & Technology, Vol. 1, Edited by Henley and Kouts, Academic Press, 1962, P. 298.) The result is a rather severe contamination of the products by radioactive fission fragments and by the fuel particles themselves. Direct exposure is necessary since about 80 percent of the fission energy is contained in the fission fragments.
In thermonuclear fusion of D-T, 80 percent of the energy is released as fast neutrons and the remaining 20 percent of the energy is released as alpha and X rays. In the fusion reaction, the material to be processed may be exposed directly to the radiation or may be exposed while being confined in a separate container. The latter condition is particularly appropriate for the neutron exposure since the neutrons have an effective penetration characteristic.
Thus, the use of fusion devices, with the resulting high energy neutrons, as well as alpha and X rays, allows for the direct interaction of the radiation with the reactants while limiting radioactivity problems to those caused by neutron capture. This difference alone is extremely significant in considering the use of thermo-nuclear reactors for cheminuclear processing.